2 * eCryptfs: Linux filesystem encryption layer
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <mcthomps@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
26 #include <linux/file.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pagemap.h>
29 #include <linux/dcache.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/fs_stack.h>
33 #include <linux/slab.h>
34 #include <linux/xattr.h>
35 #include <asm/unaligned.h>
36 #include "ecryptfs_kernel.h"
38 static struct dentry *lock_parent(struct dentry *dentry)
42 dir = dget_parent(dentry);
43 inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
47 static void unlock_dir(struct dentry *dir)
49 inode_unlock(d_inode(dir));
53 static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
55 return ecryptfs_inode_to_lower(inode) == lower_inode;
58 static int ecryptfs_inode_set(struct inode *inode, void *opaque)
60 struct inode *lower_inode = opaque;
62 ecryptfs_set_inode_lower(inode, lower_inode);
63 fsstack_copy_attr_all(inode, lower_inode);
64 /* i_size will be overwritten for encrypted regular files */
65 fsstack_copy_inode_size(inode, lower_inode);
66 inode->i_ino = lower_inode->i_ino;
67 inode->i_mapping->a_ops = &ecryptfs_aops;
69 if (S_ISLNK(inode->i_mode))
70 inode->i_op = &ecryptfs_symlink_iops;
71 else if (S_ISDIR(inode->i_mode))
72 inode->i_op = &ecryptfs_dir_iops;
74 inode->i_op = &ecryptfs_main_iops;
76 if (S_ISDIR(inode->i_mode))
77 inode->i_fop = &ecryptfs_dir_fops;
78 else if (special_file(inode->i_mode))
79 init_special_inode(inode, inode->i_mode, inode->i_rdev);
81 inode->i_fop = &ecryptfs_main_fops;
86 static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
87 struct super_block *sb)
91 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
92 return ERR_PTR(-EXDEV);
93 if (!igrab(lower_inode))
94 return ERR_PTR(-ESTALE);
95 inode = iget5_locked(sb, (unsigned long)lower_inode,
96 ecryptfs_inode_test, ecryptfs_inode_set,
100 return ERR_PTR(-EACCES);
102 if (!(inode->i_state & I_NEW))
108 struct inode *ecryptfs_get_inode(struct inode *lower_inode,
109 struct super_block *sb)
111 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
113 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
114 unlock_new_inode(inode);
121 * @lower_dentry: Existing dentry in the lower filesystem
122 * @dentry: ecryptfs' dentry
123 * @sb: ecryptfs's super_block
125 * Interposes upper and lower dentries.
127 * Returns zero on success; non-zero otherwise
129 static int ecryptfs_interpose(struct dentry *lower_dentry,
130 struct dentry *dentry, struct super_block *sb)
132 struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
135 return PTR_ERR(inode);
136 d_instantiate(dentry, inode);
141 static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
144 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
145 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
146 struct dentry *lower_dir_dentry;
150 lower_dir_dentry = lock_parent(lower_dentry);
151 rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
153 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
156 fsstack_copy_attr_times(dir, lower_dir_inode);
157 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
158 inode->i_ctime = dir->i_ctime;
161 unlock_dir(lower_dir_dentry);
168 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
169 * @ecryptfs_dentry: New file's dentry in ecryptfs
170 * @mode: The mode of the new file
172 * Creates the underlying file and the eCryptfs inode which will link to
173 * it. It will also update the eCryptfs directory inode to mimic the
174 * stat of the lower directory inode.
176 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
178 static struct inode *
179 ecryptfs_do_create(struct inode *directory_inode,
180 struct dentry *ecryptfs_dentry, umode_t mode)
183 struct dentry *lower_dentry;
184 struct dentry *lower_dir_dentry;
187 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
188 lower_dir_dentry = lock_parent(lower_dentry);
189 rc = vfs_create(d_inode(lower_dir_dentry), lower_dentry, mode, true);
191 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
192 "rc = [%d]\n", __func__, rc);
196 inode = __ecryptfs_get_inode(d_inode(lower_dentry),
197 directory_inode->i_sb);
199 vfs_unlink(d_inode(lower_dir_dentry), lower_dentry, NULL);
202 fsstack_copy_attr_times(directory_inode, d_inode(lower_dir_dentry));
203 fsstack_copy_inode_size(directory_inode, d_inode(lower_dir_dentry));
205 unlock_dir(lower_dir_dentry);
210 * ecryptfs_initialize_file
212 * Cause the file to be changed from a basic empty file to an ecryptfs
213 * file with a header and first data page.
215 * Returns zero on success
217 int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
218 struct inode *ecryptfs_inode)
220 struct ecryptfs_crypt_stat *crypt_stat =
221 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
224 if (S_ISDIR(ecryptfs_inode->i_mode)) {
225 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
226 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
229 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
230 rc = ecryptfs_new_file_context(ecryptfs_inode);
232 ecryptfs_printk(KERN_ERR, "Error creating new file "
233 "context; rc = [%d]\n", rc);
236 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
238 printk(KERN_ERR "%s: Error attempting to initialize "
239 "the lower file for the dentry with name "
240 "[%pd]; rc = [%d]\n", __func__,
241 ecryptfs_dentry, rc);
244 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
246 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
247 ecryptfs_put_lower_file(ecryptfs_inode);
254 * @dir: The inode of the directory in which to create the file.
255 * @dentry: The eCryptfs dentry
256 * @mode: The mode of the new file.
258 * Creates a new file.
260 * Returns zero on success; non-zero on error condition
263 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
264 umode_t mode, bool excl)
266 struct inode *ecryptfs_inode;
269 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
271 if (IS_ERR(ecryptfs_inode)) {
272 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
273 "lower filesystem\n");
274 rc = PTR_ERR(ecryptfs_inode);
277 /* At this point, a file exists on "disk"; we need to make sure
278 * that this on disk file is prepared to be an ecryptfs file */
279 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
281 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
283 iget_failed(ecryptfs_inode);
286 d_instantiate_new(ecryptfs_dentry, ecryptfs_inode);
291 static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
293 struct ecryptfs_crypt_stat *crypt_stat;
296 rc = ecryptfs_get_lower_file(dentry, inode);
298 printk(KERN_ERR "%s: Error attempting to initialize "
299 "the lower file for the dentry with name "
300 "[%pd]; rc = [%d]\n", __func__,
305 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
306 /* TODO: lock for crypt_stat comparison */
307 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
308 ecryptfs_set_default_sizes(crypt_stat);
310 rc = ecryptfs_read_and_validate_header_region(inode);
311 ecryptfs_put_lower_file(inode);
313 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
315 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
318 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
323 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
325 static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
326 struct dentry *lower_dentry)
328 struct path *path = ecryptfs_dentry_to_lower_path(dentry->d_parent);
329 struct inode *inode, *lower_inode;
330 struct ecryptfs_dentry_info *dentry_info;
333 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
336 return ERR_PTR(-ENOMEM);
339 fsstack_copy_attr_atime(d_inode(dentry->d_parent),
340 d_inode(path->dentry));
341 BUG_ON(!d_count(lower_dentry));
343 ecryptfs_set_dentry_private(dentry, dentry_info);
344 dentry_info->lower_path.mnt = mntget(path->mnt);
345 dentry_info->lower_path.dentry = lower_dentry;
348 * negative dentry can go positive under us here - its parent is not
349 * locked. That's OK and that could happen just as we return from
350 * ecryptfs_lookup() anyway. Just need to be careful and fetch
351 * ->d_inode only once - it's not stable here.
353 lower_inode = READ_ONCE(lower_dentry->d_inode);
356 /* We want to add because we couldn't find in lower */
360 inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
362 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
363 __func__, PTR_ERR(inode));
364 return ERR_CAST(inode);
366 if (S_ISREG(inode->i_mode)) {
367 rc = ecryptfs_i_size_read(dentry, inode);
369 make_bad_inode(inode);
374 if (inode->i_state & I_NEW)
375 unlock_new_inode(inode);
376 return d_splice_alias(inode, dentry);
381 * @ecryptfs_dir_inode: The eCryptfs directory inode
382 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
383 * @flags: lookup flags
385 * Find a file on disk. If the file does not exist, then we'll add it to the
386 * dentry cache and continue on to read it from the disk.
388 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
389 struct dentry *ecryptfs_dentry,
392 char *encrypted_and_encoded_name = NULL;
393 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
394 struct dentry *lower_dir_dentry, *lower_dentry;
395 const char *name = ecryptfs_dentry->d_name.name;
396 size_t len = ecryptfs_dentry->d_name.len;
400 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
402 mount_crypt_stat = &ecryptfs_superblock_to_private(
403 ecryptfs_dentry->d_sb)->mount_crypt_stat;
404 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
405 rc = ecryptfs_encrypt_and_encode_filename(
406 &encrypted_and_encoded_name, &len,
407 mount_crypt_stat, name, len);
409 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
410 "filename; rc = [%d]\n", __func__, rc);
413 name = encrypted_and_encoded_name;
416 lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
417 if (IS_ERR(lower_dentry)) {
418 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
419 "[%ld] on lower_dentry = [%s]\n", __func__,
420 PTR_ERR(lower_dentry),
422 res = ERR_CAST(lower_dentry);
424 res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
426 kfree(encrypted_and_encoded_name);
430 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
431 struct dentry *new_dentry)
433 struct dentry *lower_old_dentry;
434 struct dentry *lower_new_dentry;
435 struct dentry *lower_dir_dentry;
439 file_size_save = i_size_read(d_inode(old_dentry));
440 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
441 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
442 dget(lower_old_dentry);
443 dget(lower_new_dentry);
444 lower_dir_dentry = lock_parent(lower_new_dentry);
445 rc = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry),
446 lower_new_dentry, NULL);
447 if (rc || d_really_is_negative(lower_new_dentry))
449 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
452 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
453 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
454 set_nlink(d_inode(old_dentry),
455 ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
456 i_size_write(d_inode(new_dentry), file_size_save);
458 unlock_dir(lower_dir_dentry);
459 dput(lower_new_dentry);
460 dput(lower_old_dentry);
464 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
466 return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
469 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
473 struct dentry *lower_dentry;
474 struct dentry *lower_dir_dentry;
475 char *encoded_symname;
476 size_t encoded_symlen;
477 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
479 lower_dentry = ecryptfs_dentry_to_lower(dentry);
481 lower_dir_dentry = lock_parent(lower_dentry);
482 mount_crypt_stat = &ecryptfs_superblock_to_private(
483 dir->i_sb)->mount_crypt_stat;
484 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
486 mount_crypt_stat, symname,
490 rc = vfs_symlink(d_inode(lower_dir_dentry), lower_dentry,
492 kfree(encoded_symname);
493 if (rc || d_really_is_negative(lower_dentry))
495 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
498 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
499 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
501 unlock_dir(lower_dir_dentry);
503 if (d_really_is_negative(dentry))
508 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
511 struct dentry *lower_dentry;
512 struct dentry *lower_dir_dentry;
514 lower_dentry = ecryptfs_dentry_to_lower(dentry);
515 lower_dir_dentry = lock_parent(lower_dentry);
516 rc = vfs_mkdir(d_inode(lower_dir_dentry), lower_dentry, mode);
517 if (rc || d_really_is_negative(lower_dentry))
519 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
522 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
523 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
524 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
526 unlock_dir(lower_dir_dentry);
527 if (d_really_is_negative(dentry))
532 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
534 struct dentry *lower_dentry;
535 struct dentry *lower_dir_dentry;
538 lower_dentry = ecryptfs_dentry_to_lower(dentry);
540 lower_dir_dentry = lock_parent(lower_dentry);
542 rc = vfs_rmdir(d_inode(lower_dir_dentry), lower_dentry);
544 if (!rc && d_really_is_positive(dentry))
545 clear_nlink(d_inode(dentry));
546 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
547 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
548 unlock_dir(lower_dir_dentry);
556 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
559 struct dentry *lower_dentry;
560 struct dentry *lower_dir_dentry;
562 lower_dentry = ecryptfs_dentry_to_lower(dentry);
563 lower_dir_dentry = lock_parent(lower_dentry);
564 rc = vfs_mknod(d_inode(lower_dir_dentry), lower_dentry, mode, dev);
565 if (rc || d_really_is_negative(lower_dentry))
567 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
570 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
571 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
573 unlock_dir(lower_dir_dentry);
574 if (d_really_is_negative(dentry))
580 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
581 struct inode *new_dir, struct dentry *new_dentry,
585 struct dentry *lower_old_dentry;
586 struct dentry *lower_new_dentry;
587 struct dentry *lower_old_dir_dentry;
588 struct dentry *lower_new_dir_dentry;
589 struct dentry *trap = NULL;
590 struct inode *target_inode;
595 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
596 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
597 dget(lower_old_dentry);
598 dget(lower_new_dentry);
599 lower_old_dir_dentry = dget_parent(lower_old_dentry);
600 lower_new_dir_dentry = dget_parent(lower_new_dentry);
601 target_inode = d_inode(new_dentry);
602 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
603 /* source should not be ancestor of target */
604 if (trap == lower_old_dentry) {
608 /* target should not be ancestor of source */
609 if (trap == lower_new_dentry) {
613 rc = vfs_rename(d_inode(lower_old_dir_dentry), lower_old_dentry,
614 d_inode(lower_new_dir_dentry), lower_new_dentry,
619 fsstack_copy_attr_all(target_inode,
620 ecryptfs_inode_to_lower(target_inode));
621 fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
622 if (new_dir != old_dir)
623 fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
625 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
626 dput(lower_new_dir_dentry);
627 dput(lower_old_dir_dentry);
628 dput(lower_new_dentry);
629 dput(lower_old_dentry);
633 static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
635 DEFINE_DELAYED_CALL(done);
636 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
641 link = vfs_get_link(lower_dentry, &done);
643 return ERR_CAST(link);
645 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
647 do_delayed_call(&done);
654 static const char *ecryptfs_get_link(struct dentry *dentry,
656 struct delayed_call *done)
662 return ERR_PTR(-ECHILD);
664 buf = ecryptfs_readlink_lower(dentry, &len);
667 fsstack_copy_attr_atime(d_inode(dentry),
668 d_inode(ecryptfs_dentry_to_lower(dentry)));
670 set_delayed_call(done, kfree_link, buf);
675 * upper_size_to_lower_size
676 * @crypt_stat: Crypt_stat associated with file
677 * @upper_size: Size of the upper file
679 * Calculate the required size of the lower file based on the
680 * specified size of the upper file. This calculation is based on the
681 * number of headers in the underlying file and the extent size.
683 * Returns Calculated size of the lower file.
686 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
691 lower_size = ecryptfs_lower_header_size(crypt_stat);
692 if (upper_size != 0) {
695 num_extents = upper_size >> crypt_stat->extent_shift;
696 if (upper_size & ~crypt_stat->extent_mask)
698 lower_size += (num_extents * crypt_stat->extent_size);
705 * @dentry: The ecryptfs layer dentry
706 * @ia: Address of the ecryptfs inode's attributes
707 * @lower_ia: Address of the lower inode's attributes
709 * Function to handle truncations modifying the size of the file. Note
710 * that the file sizes are interpolated. When expanding, we are simply
711 * writing strings of 0's out. When truncating, we truncate the upper
712 * inode and update the lower_ia according to the page index
713 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
714 * the caller must use lower_ia in a call to notify_change() to perform
715 * the truncation of the lower inode.
717 * Returns zero on success; non-zero otherwise
719 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
720 struct iattr *lower_ia)
723 struct inode *inode = d_inode(dentry);
724 struct ecryptfs_crypt_stat *crypt_stat;
725 loff_t i_size = i_size_read(inode);
726 loff_t lower_size_before_truncate;
727 loff_t lower_size_after_truncate;
729 if (unlikely((ia->ia_size == i_size))) {
730 lower_ia->ia_valid &= ~ATTR_SIZE;
733 rc = ecryptfs_get_lower_file(dentry, inode);
736 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
737 /* Switch on growing or shrinking file */
738 if (ia->ia_size > i_size) {
739 char zero[] = { 0x00 };
741 lower_ia->ia_valid &= ~ATTR_SIZE;
742 /* Write a single 0 at the last position of the file;
743 * this triggers code that will fill in 0's throughout
744 * the intermediate portion of the previous end of the
745 * file and the new and of the file */
746 rc = ecryptfs_write(inode, zero,
747 (ia->ia_size - 1), 1);
748 } else { /* ia->ia_size < i_size_read(inode) */
749 /* We're chopping off all the pages down to the page
750 * in which ia->ia_size is located. Fill in the end of
751 * that page from (ia->ia_size & ~PAGE_MASK) to
752 * PAGE_SIZE with zeros. */
753 size_t num_zeros = (PAGE_SIZE
754 - (ia->ia_size & ~PAGE_MASK));
756 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
757 truncate_setsize(inode, ia->ia_size);
758 lower_ia->ia_size = ia->ia_size;
759 lower_ia->ia_valid |= ATTR_SIZE;
765 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
770 rc = ecryptfs_write(inode, zeros_virt,
771 ia->ia_size, num_zeros);
774 printk(KERN_ERR "Error attempting to zero out "
775 "the remainder of the end page on "
776 "reducing truncate; rc = [%d]\n", rc);
780 truncate_setsize(inode, ia->ia_size);
781 rc = ecryptfs_write_inode_size_to_metadata(inode);
783 printk(KERN_ERR "Problem with "
784 "ecryptfs_write_inode_size_to_metadata; "
788 /* We are reducing the size of the ecryptfs file, and need to
789 * know if we need to reduce the size of the lower file. */
790 lower_size_before_truncate =
791 upper_size_to_lower_size(crypt_stat, i_size);
792 lower_size_after_truncate =
793 upper_size_to_lower_size(crypt_stat, ia->ia_size);
794 if (lower_size_after_truncate < lower_size_before_truncate) {
795 lower_ia->ia_size = lower_size_after_truncate;
796 lower_ia->ia_valid |= ATTR_SIZE;
798 lower_ia->ia_valid &= ~ATTR_SIZE;
801 ecryptfs_put_lower_file(inode);
805 static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
807 struct ecryptfs_crypt_stat *crypt_stat;
808 loff_t lower_oldsize, lower_newsize;
810 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
811 lower_oldsize = upper_size_to_lower_size(crypt_stat,
813 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
814 if (lower_newsize > lower_oldsize) {
816 * The eCryptfs inode and the new *lower* size are mixed here
817 * because we may not have the lower i_mutex held and/or it may
818 * not be appropriate to call inode_newsize_ok() with inodes
819 * from other filesystems.
821 return inode_newsize_ok(inode, lower_newsize);
829 * @dentry: The ecryptfs layer dentry
830 * @new_length: The length to expand the file to
832 * Simple function that handles the truncation of an eCryptfs inode and
833 * its corresponding lower inode.
835 * Returns zero on success; non-zero otherwise
837 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
839 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
840 struct iattr lower_ia = { .ia_valid = 0 };
843 rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
847 rc = truncate_upper(dentry, &ia, &lower_ia);
848 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
849 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
851 inode_lock(d_inode(lower_dentry));
852 rc = notify_change(lower_dentry, &lower_ia, NULL);
853 inode_unlock(d_inode(lower_dentry));
859 ecryptfs_permission(struct inode *inode, int mask)
861 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
866 * @dentry: dentry handle to the inode to modify
867 * @ia: Structure with flags of what to change and values
869 * Updates the metadata of an inode. If the update is to the size
870 * i.e. truncation, then ecryptfs_truncate will handle the size modification
871 * of both the ecryptfs inode and the lower inode.
873 * All other metadata changes will be passed right to the lower filesystem,
874 * and we will just update our inode to look like the lower.
876 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
879 struct dentry *lower_dentry;
880 struct iattr lower_ia;
882 struct inode *lower_inode;
883 struct ecryptfs_crypt_stat *crypt_stat;
885 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
886 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {
887 rc = ecryptfs_init_crypt_stat(crypt_stat);
891 inode = d_inode(dentry);
892 lower_inode = ecryptfs_inode_to_lower(inode);
893 lower_dentry = ecryptfs_dentry_to_lower(dentry);
894 mutex_lock(&crypt_stat->cs_mutex);
895 if (d_is_dir(dentry))
896 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
897 else if (d_is_reg(dentry)
898 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
899 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
900 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
902 mount_crypt_stat = &ecryptfs_superblock_to_private(
903 dentry->d_sb)->mount_crypt_stat;
904 rc = ecryptfs_get_lower_file(dentry, inode);
906 mutex_unlock(&crypt_stat->cs_mutex);
909 rc = ecryptfs_read_metadata(dentry);
910 ecryptfs_put_lower_file(inode);
912 if (!(mount_crypt_stat->flags
913 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
915 printk(KERN_WARNING "Either the lower file "
916 "is not in a valid eCryptfs format, "
917 "or the key could not be retrieved. "
918 "Plaintext passthrough mode is not "
919 "enabled; returning -EIO\n");
920 mutex_unlock(&crypt_stat->cs_mutex);
924 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
925 | ECRYPTFS_ENCRYPTED);
928 mutex_unlock(&crypt_stat->cs_mutex);
930 rc = setattr_prepare(dentry, ia);
933 if (ia->ia_valid & ATTR_SIZE) {
934 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
939 memcpy(&lower_ia, ia, sizeof(lower_ia));
940 if (ia->ia_valid & ATTR_FILE)
941 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
942 if (ia->ia_valid & ATTR_SIZE) {
943 rc = truncate_upper(dentry, ia, &lower_ia);
949 * mode change is for clearing setuid/setgid bits. Allow lower fs
950 * to interpret this in its own way.
952 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
953 lower_ia.ia_valid &= ~ATTR_MODE;
955 inode_lock(d_inode(lower_dentry));
956 rc = notify_change(lower_dentry, &lower_ia, NULL);
957 inode_unlock(d_inode(lower_dentry));
959 fsstack_copy_attr_all(inode, lower_inode);
963 static int ecryptfs_getattr_link(const struct path *path, struct kstat *stat,
964 u32 request_mask, unsigned int flags)
966 struct dentry *dentry = path->dentry;
967 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
970 mount_crypt_stat = &ecryptfs_superblock_to_private(
971 dentry->d_sb)->mount_crypt_stat;
972 generic_fillattr(d_inode(dentry), stat);
973 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
977 target = ecryptfs_readlink_lower(dentry, &targetsiz);
978 if (!IS_ERR(target)) {
980 stat->size = targetsiz;
982 rc = PTR_ERR(target);
988 static int ecryptfs_getattr(const struct path *path, struct kstat *stat,
989 u32 request_mask, unsigned int flags)
991 struct dentry *dentry = path->dentry;
992 struct kstat lower_stat;
995 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat,
996 request_mask, flags);
998 fsstack_copy_attr_all(d_inode(dentry),
999 ecryptfs_inode_to_lower(d_inode(dentry)));
1000 generic_fillattr(d_inode(dentry), stat);
1001 stat->blocks = lower_stat.blocks;
1007 ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
1008 const char *name, const void *value,
1009 size_t size, int flags)
1012 struct dentry *lower_dentry;
1014 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1015 if (!(d_inode(lower_dentry)->i_opflags & IOP_XATTR)) {
1019 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1021 fsstack_copy_attr_all(inode, d_inode(lower_dentry));
1027 ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
1028 const char *name, void *value, size_t size)
1032 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1036 inode_lock(lower_inode);
1037 rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
1038 inode_unlock(lower_inode);
1044 ecryptfs_getxattr(struct dentry *dentry, struct inode *inode,
1045 const char *name, void *value, size_t size)
1047 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
1048 ecryptfs_inode_to_lower(inode),
1053 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1056 struct dentry *lower_dentry;
1058 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1059 if (!d_inode(lower_dentry)->i_op->listxattr) {
1063 inode_lock(d_inode(lower_dentry));
1064 rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
1065 inode_unlock(d_inode(lower_dentry));
1070 static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
1074 struct dentry *lower_dentry;
1075 struct inode *lower_inode;
1077 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1078 lower_inode = ecryptfs_inode_to_lower(inode);
1079 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1083 inode_lock(lower_inode);
1084 rc = __vfs_removexattr(lower_dentry, name);
1085 inode_unlock(lower_inode);
1090 const struct inode_operations ecryptfs_symlink_iops = {
1091 .get_link = ecryptfs_get_link,
1092 .permission = ecryptfs_permission,
1093 .setattr = ecryptfs_setattr,
1094 .getattr = ecryptfs_getattr_link,
1095 .listxattr = ecryptfs_listxattr,
1098 const struct inode_operations ecryptfs_dir_iops = {
1099 .create = ecryptfs_create,
1100 .lookup = ecryptfs_lookup,
1101 .link = ecryptfs_link,
1102 .unlink = ecryptfs_unlink,
1103 .symlink = ecryptfs_symlink,
1104 .mkdir = ecryptfs_mkdir,
1105 .rmdir = ecryptfs_rmdir,
1106 .mknod = ecryptfs_mknod,
1107 .rename = ecryptfs_rename,
1108 .permission = ecryptfs_permission,
1109 .setattr = ecryptfs_setattr,
1110 .listxattr = ecryptfs_listxattr,
1113 const struct inode_operations ecryptfs_main_iops = {
1114 .permission = ecryptfs_permission,
1115 .setattr = ecryptfs_setattr,
1116 .getattr = ecryptfs_getattr,
1117 .listxattr = ecryptfs_listxattr,
1120 static int ecryptfs_xattr_get(const struct xattr_handler *handler,
1121 struct dentry *dentry, struct inode *inode,
1122 const char *name, void *buffer, size_t size)
1124 return ecryptfs_getxattr(dentry, inode, name, buffer, size);
1127 static int ecryptfs_xattr_set(const struct xattr_handler *handler,
1128 struct dentry *dentry, struct inode *inode,
1129 const char *name, const void *value, size_t size,
1133 return ecryptfs_setxattr(dentry, inode, name, value, size, flags);
1135 BUG_ON(flags != XATTR_REPLACE);
1136 return ecryptfs_removexattr(dentry, inode, name);
1140 const struct xattr_handler ecryptfs_xattr_handler = {
1141 .prefix = "", /* match anything */
1142 .get = ecryptfs_xattr_get,
1143 .set = ecryptfs_xattr_set,
1146 const struct xattr_handler *ecryptfs_xattr_handlers[] = {
1147 &ecryptfs_xattr_handler,